If the solubility product of CuS is

Solubility product of CuS, Ksp = 6 × 10−16

Let s be the solubility of CuS in mol L−1.

Now, 

= s × s

= s2

Then, we have, $K_{\mathrm{sp}}=s^{2}=6 \times 10^{-16}$

$\Rightarrow s=\sqrt{6 \times 10^{-16}}$

= 2.45 × 10−8 mol L−1

Hence, the maximum molarity of CuS in an aqueous solution is 2.45 × 10−8 mol L−1.